1. Field of the Invention
The present invention relates in general to pneumatic, hydraulic, and hydropenumatic piston/cylinder devices and pertains in particular to an improved piston unit and piston rod structure for such devices and to and improved method of assembly of the piston unit and piston rod to one another and within the cylinder.
2. The Prior Art
It is known in prior art cylinder-piston devices, as illustrated by U.S. Pat. No. 4,089,512 for instance, to mount a piston unit on the inner end of a piston rod unit for axial movement therealong between two axial limiting positions defined by abutment surfaces carried by the piston rod. The axially-outermost abutment surface is positioned on the piston rod before the piston unit has been mounted on the piston rod. Whenever disassembly of the piston unit and the piston rod are required, e.g. for repair, however, it is necessary in such prior art devices to deform the member or members defining the second abutment surface, again by means of a tool. This is not only time consuming, but subjects the piston rod and/or the abutment surface-defining member(s) to wear and possible damage.